Ball-mill.



Patented Aug. 6, 1918.

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BALL MILL.

y APPLICATION FILED MAY 3l" |91?. 1,275,184..

0.11. FAIRCHILD.

BALLMlLL. l APPLICALHON FILED MAYah 19|?.

Patented Aug. 6, 1918.

3 SHEETS-SHEET 2.

vwevwoz D. H. FAIRCHILD.`

BALL MILL. APPLlcATlo'N FILED MAYal. 1911.

1,275,184. f Patented Aug. 6,1918.

3 SHEETS-SHEET 3.

DONALD H. FAIRCHILD, 0F DENVER, COLORADO.

BALL-MILL.

Specification of Letters Patent.

lPatcn'tcdl Aug. 6, 1918.

Application mea May 31` 1917. serial No. 171,902.

To all whom t may concern:

Be it known that I, DONALD H. a citizenv of the United States, the Princess Apartments,- and county of Denver and FAIRCHILD, reslding at State of Colorado,

have invented certain new and useful Im-` provements in Ball-Mills; and I do declare the following ,to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which"l form apart of this specification. l

My invention relates to improvements in ball or pebble mills, my object being to provide a construction of this class which shall have several improvements over those in ordinary use, so far as I am aware. My object is to provide a mill of this character in which the product shall be characterized by less slime, and which shall also have a greater capacity than the mills of this type heretofore in vogue. In the accomplishment of this result I make provision for discharging 4the pulverized product at both ends of the machine. Heretofore, so far as I am aware, the discharge from mills of this type has been at one end only, being the end remote from the feed end. It is well understood that grinding devices of this characteri are mounted upon end trunnions.

lar form of the well known construction both ofthese trunnions are hollow, the mate-r rial being fed by a screw through one of the hollow trunnions, while the pulverized or granulated product is discharged throl'igh the other hollow trunnion. In my improvement I make lprovision for discharging through the feedy trunnion aswell as the opposite trunnion, and tothis endI provide an annular discharge passage around the inner feed passage in which the feed-screw or spiral-thread is arranged. By making rovision for a discharge at the feed end o the mill, I am able to prevent the sliming of the product to a large extent, since the matefine early in the ace grates at the feed rial which is suilicientl tion to pass through t end of the mill, will pass into the ribbed compartmentsl and be carried upwardly and discharged through the annular discharge opening at the feed end of the structure.

Having brieliy outlined my improvement, I will proceed to describethe same in detail,

, drawings, 1n w #25, in the city In the regu- .equipped with a cnical reference bein ich is illustrated an lembodiment thereof. 4

' In this drawing Figure 1 is a central longitudinal section "taken through my improved ball or pebble mill.

Fig. 2 is a transverse section taken on the line 2 2 Fig. 1, loo toward the right.

Fig. 3 is a'section ta. en on the line 3 3, Fig. '1, the parts being scale.

Fig. v4 is a section taken on the line 4 4, Fig. 1.

r Fig. 5 is a section taken Fig. 1.

Fig. 6`is a section taken on the line 6 6, Fig. 1. e

The same reference characters indicate the on the-line 5 5,

same partsin all the views.

located. The cylindrical shell is centrally I provided with two openings, which I will designate by the numerals 9 and 10 respectively. Within this cylindrical casing` is mounted liners 12, which cover the interior circumferential surface of the structure between the end grates 3 and 4, said grates being spaced from the heads 14 and 15 by ribs 16 and 17, forming relatively narrow sectorshape compartments between the grates and the heads, the openings in the grates being of lsuch size as to properly regulate the escape of the pulverized or granular product. The grate 3 is provided with a central liner 47 ,which is suitably secured to the adjacent head ofl the structure, said liner being member 18, which points outwardly into the opening 9 and guides the material after it is carried upwardly and dropped by the rotary action of made to the accompanying shown on a larger i Vthe mill into a hollow discharge trunnion19.

threaded for the purpose of feeding the material Ato be treated into the pulverizing chamber of the structure, the outer ex- 4tremity of the' feed opening lbeing in com- 30 which facilitates the discharge ofv thel' munication with a feed scoop 23 which takes the material from a supply receptacle 24 and carries -it upwardly and delivers it to the feed-screw of the sleeve. rljhe said sleeve 21 is spaced from the trunnion 25 providing a discharge space 26 around the sleeve. The sleeve and the trunnion 4proper are spaced from each other by means of lugs 27 and 28 which are circumferentially spaced, as shown at 29, to make room for the discharge of the product at the feed end of the machine. rlhe outer end ofthe trunnion 25 is equipped with an outwardly, flaring member product into a launder 31 of any suitable character.

As shown in the drawing the grates 3 and 4 are each composed of a number of sectorshaped members 32, the grates as well as the liners being preferably formed in sections of such size that they may be replaced at small cost, when any l part becomes suliiciently wornto require the substitution of a new part. I

When the structure is in use, the trunnions are engaged by suitable boxes 33,

which are supported upon pedestals 34 of any suitable construction. When in use the mill is rotated by the employment of any suitable power which may be applied through a large gear 35, a meshing pinion 36 being employed for driving purposes, the pinion beingactuated by a motor of suitable character. As the structure is rotated it carries the scoop 23, which takes the mate- A rial to be treated from the receptacle 24 and delivers it to the feed-screw of the sleeve 21,

' which carries it into the chamber of the rotary mill, where it is acted on by the balls orfpebbles employedl for pulverizing purposes. By virtue of the fact that provision is made for a discharge of the pulverized materialat the feed extremity of the mill,

the material which is suflicientlygranulated or pulverized after, or 'shortly'after it 'enters the mill, will p ass through the grate 4 at the feed end, and will be carried upwardly in the sector-shaped compartments which are formed by the ribs 16 and 17, between the grates and the heads as heretofore explained; and this material, after it reaches ay suflicient elevation in the said compartments, w11l be discharged into the space 26 between the trunnion and the sleeve carrying the feed-screw, and will finally escape atl the iarin extremity 3() of the trunnion. At the same time, the product is also being discharged through the. hollow trunnion 19 at the opposite extremity of the mill from the feed-screw. Hence, it will be understood that my improved mill. is equipped for a double discharge of the pulverized product, thus greatly increasing the capacity of the mill for a given tonnage of ore, and also preventing the sliming. of the material treated, to a very large extent.

Attention is called to the fact that the grate 3 is secured to the adjacent head 14 of' the mill by means of bolts 37. This grate is so interlocked with the central liner 47 that the latter is held in place by the grate. lt should be explained that the cone 18 is provided with ribs 40 which coincide as to position with the ribs 16 of the adj cent` head 14 of the mill in order to form continuous passages from the sectonshape compartments.

feed opening at one end anda central discharge opening at each end thereof,-and segregating and delivering means for each discharge opening.

2. A ball or pebble mill having a central feed passage at one end and a. central discharge passage at each end thereof, grates spaced inwardly from the outer heads of the mill, and means arranged between each grate and the corresponding head for elevating the pulverized material to the adjacent discharge passage.

3. A cylindrical ball or pebble mill having a central feed passage at one end and a central discharge passage at each end thereof, means at each end of the mill for 'segregating the pulverized material, and meansv DONALD` H. 'FARCHILD. 

